Three ways to delete a row while navigate over a RowSet

An OTN user ask how to delete a row while navigation a row set. This question and the problem the user got with implementing this leads to this sample. Shay Shmeltzer mentioned a pending bug #12671112 in JDev 11.1.2 which may cause trouble deleting a row while navigation a row set. As far as I understand only the first method (direct delete via data control) is affected by the bug.

The are a couple of ways to archive this task. This sample uses the declarative way of doing this. So no bean code is involved. I’m using the HR schema and the departments table to show the techniques. Be sure to save the content of the DEPARTMENTS table as the deletion will remove some rows if you commit the operation. For this you can e.g. export the table content as SQL insert statements to a file.

You can download the sample code from here
You need to remove the suffix ‘.doc’ as the file itself is a zip archive.

The sample shows three approaches to the problem, all declarative.
First I use the ‘Delete’ method from the DataControl ViewObject to delete the currently selected row.
The second approach uses a custom method in th e VO which gets the department id to remove as a parameter.
Finally the third approach uses a task flow method call to the above mentioned method to archive the deletion of the row which is identified by the passed department id.

Final application

Final application

The application consists of a ADF form together with the navigation buttons, commit and rollback button and one button to activate each of the three solutions.

1. Solution

The delete button is bound directly to the ‘Delete’ method of the VO of the DataControl:

<af:commandButton actionListener="#{bindings.Delete.execute}"
    text="Delete" immediate="true" id="cb9"/>

and the binding

Delete Binding

Delete Binding

As mentioned above the solution might cause trouble. For more info read this thread.

2. Solution

The second approach uses a custom method which is implemented in the DepartmentViewObject. The method receives the department id to delete as parameter, uses a viewCriteria to find the row and deletes the row if found. The method is exposed in the client interface of the VO to make it accessible on the UI layer.

    /** Delete the department row with the department id aDepId
     * Search the department via its id and if found delete the row without committing
     * @param aDepId Id of the department to delete
    public void deleteDepartmentById(Number aDepId)
        ViewCriteria lCriteria = this.getViewCriteria("DepartmentByIdCriteria");
        Row row = this.first();
        if (row != null)
  "Row with DepId " + aDepId.toString() + " deleted (not committed yet)!");
  "Row with DepId " + aDepId.toString() + " not found!");

The button ‘deleteDepartmentById’ binds this method to the button

<af:commandButton actionListener="#{bindings.deleteDepartmentById.execute}"
    id="cb7" immediate="true"/>

and the binding of the method

Binding DeleteDepartmentById

Binding DeleteDepartmentById

In this case the selected department id is passed to the method directly in the binding dialog (which is opened when you drop a method which needs a parameter onto the page:
Edit Action Binding of DeleteDepartmentById

Edit Action Binding of DeleteDepartmentById

3. Solution

The final approach used the same method mentioned in the 2nd approach, but uses a task flow method call to execute it.

Task Flow Method Call

Task Flow Method Call

The Button uses a af:setPropertyListener to pass the selected department id to the method in pageFlowScope variable ‘#{pageFlowScope.depId}’

<af:commandButton text="Delete Row via TaskFlow" id="cb8"
    action="delete" immediate="true">
    <af:setPropertyListener from="#{bindings.DepartmentId.inputValue}"

The task flow method call was dropped from the dataControl onto the bounded task flow. The picture below shows the pageDef file which was generated by the framework:

PageDef of Method in TaskFlow

PageDef of Method in TaskFlow

This time the parameter is read from the pageFlowScope variable ‘#{pageFlowScope.depId}’.

All three solutions are doing the same in the end: they delete a row from a row set. Solutions 2 and 3 can be used when the table you use to select the row is based on an other (e.g. read only) VO then the VO you use to delete the row.
The same technique can be used for other methods defined in the VO too, e.g. to select a row in a read only table and edit the row in a ADF form (using a method which find the row ba id).


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